You may have hit a surge of search engine spiders. Out illustrious Webbie is always trying to promote this site and as a result has submitted this site to all of the search engines. Their bots/scripts/spiders (whatever title you choose to use) 'crawl' the site, gathering word content for key-word searches.

When you type in certain key-words like 'kilt', 'sporran', etc., the search engines will give X Marks as a return, since they have harvested data on the forum.

Of course, the more the search engines return X Marks to those searches, the more human visitors you will see.